The present disclosure relates to electro-photographic printing devices, such as laser printers and the like. The electro-photographic (EP) drum in a typical electro-photographic printer is typically designed to last a certain number of rotations, based upon the page yield of the toner cartridge, plus a certain amount of margin. In certain usage conditions, however, such as when printing on narrow media, the drum can wear out when there is still a significant amount of toner remaining in the cartridge.
One of the major contributors to wear of the printer drum is friction between the surface of the drum and a cleaning blade, which is positioned against the drum and removes un-transferred toner from it prior to development. Residual toner on the drum normally serves as a lubricant and reduces friction with the cleaning blade during normal use. However, in cases where a user prints on narrow media (such as envelopes), or prints a pattern with uneven distribution of toner across the page width (e.g. columns of numbers) there can be substantial areas in which no toner is applied to the drum, resulting in increased friction for those areas. This can lead to uneven wear of the drum and ultimately to failure of the charge transport layer of the drum. This can result in print quality defects, and, ultimately, the leaking of toner into the printer.